Adrenergic drugs- direct acting Catecholamines

Question 1

MoA of Adrenergic drugs?

Answer 1

Stimulate α & β adrenergic and dopamine receptors –> mimic the action of Epinephrine (E) & Norepinephrine (NE).

Question 2

Subtypes of Adrenergic drugs

Answer 2

Catecholamines & non-catecholamines

Question 3

MoA of Catecholamine drugs

Answer 3

direct-acting, indirect-acting & dual-acting.

Question 4

Routes of Administraions of Cathecolamines

Answer 4

Intramuscullary (I.M.)–> rapid absorptin

others :
NOT orally used –> metabolized by digestive enzymes.
SL –> rapid absorption through mucus membranes.
S.C –> slow absorption

Question 5

Metabolism of Catecholamines

Answer 5

–> Meablised in the liver (COMT and MAO)
also in the GI tract, lungs, kidneys, plasma, other tissues

Question 6

Routes of administration of Non-Catecholamines

Answer 6

1) Oral drugs- GI tract absorption–> wide distribution
2) Inhaled drugs - gradual absorption from bronchi –> lower drug levels in the body
(e.g., Albuterol aka salbutamol for acute Asthma)

Question 7

Adverse effects of Catecholamines

Answer 7

1) Palpitation
2) Tremors
3) Hypotension/ Hypertension
4) Stroke
5) Increased blood glucose levels

Question 8

Name a few Direct-acting Catecholamine drugs

Answer 8

1) Epinephrine (Anaphylaxis &Asthma)
2) Norepinephrine ( Hypotension & Septic shock)
3) Dopamine (HF & unstable bradycardia)
4) Isoproterenol (Nebulizer acute asthma)
5) Dobutamine (HF)

Question 9

Name a few direct-acting Non-Catecholamine drugs

Answer 9

1) Phenylephrine (nasal decongestant)
2) Clonidine & Methyldopa (mild/moderate Hypertension)
3) Isoproterenol (Bronchospasm, Heart block)
4) Dobutamine (CHF)
5) Albuterl -aka Salbutamol (Acute asthma/COPD)
6) Trebutaline (Premature labor)

Question 10

Indication of Norepinepherine

Answer 10

1) Septic shock
2) Hypotension

Question 11

MoA of Norepinepherine

Answer 11

NE effects : α1, α2, β1
–> α1- ↑ BP & ↑ TPR
–> β1- ↑HR, ↑SV, ↑CO, ↑ pulse pressure
–> potenital refelx bradychardia
NO EFFECT ON β2

Question 12

Administration of Norepinephrine

Answer 12

IV admin only.

Question 13

Adverse Effects of Norepinephrine

Answer 13

1) Vasospasm,
2) tissue necrosis,
3) excessive blood pressure increase,
4) arrhythmias,
5) cardiac infraction

Question 14

Indication of Epinephrine

Answer 14

1) Anaphylaxis
2) Asthma

Question 15

MoA of Epinephrine

Answer 15

1) Dose-dependent effects:
- Low-dose: β1, β2 stimulation
- High-dose: α1, β1 (β2).

2) β2-specific effects:
- Smooth muscle relaxation: bronchioles, uterus, blood vessels

3) Metabolic effects:
- ↑ glycogenolysis (muscle and liver).
- ↑ gluconeogenesis.
- ↑ mobilization and use of fat

Question 16

Administration of Epinephrine

Answer 16

–> Parenteral and topical only
- Does not enter CNS.
- Duration –> short.

Question 17

Which receptors does Dopamine affect?

Answer 17

a1, a2, b1, b2, D1 agonist.

Question 18

Administration of Dopamine

Answer 18

IV admin only.

Question 19

Adverse effects of Dopamine

Answer 19

1) Cardiovascular disturbance, &
2) arrhythmias

Question 20

Which receptors does Isoproterenol affect?

Answer 20

β1, β2, β3 agonist

Question 21

Indication of Dopamine

Answer 21

1) Renal shock
2) HF

Question 22

Indication of Isoproterenol

Answer 22

Primary use:
1. nebulizer (acute asthma).
2. IV (in AV block)

Question 23

Which receptors does Dobutamine affect?

Answer 23

β1 agonist

Question 24

Indication of Dobutamine

Answer 24

primary use:
1. Acute heart failure to increase
cardiac output.